Elastic body for coating metal and other uses



Patented Oct. 6, 1936 UNITED STATES ELASTIC BODY FOR COATING METAL ANDOTHER USES Werner W. Duecker and Claron R. Payne, Pittsburgh, Pa.,assignors to Texas Gulf Sulphur Company, a corporation of Texas NoDrawing. Application September 4, 1934, Serial No. 742,641

1 Claim.

This invention relates to the production of elastic and rubber-likebodies, and the coating of articles of metal therewith.

Effort in the past has been made to vulcanize upon the surfaces of metalarticles an adherent, rubber-like coating, but without success.

We have discovered a composition of a plastic with particular metalcompounds that, being applied to metal surfaces and vulcanized in situ,afiords the desired result. Our composition, being vulcanized, isconverted into a rubber-like mass of permanent character, and as such isof wider and general utility; but, as a coating for metal, it findsimmediate practical use.

There is a class of plastics, known to industry, that consists of orincludes the mutual solution of sulphur and olefine sulphide. Such anarticle is disclosed in United States Letters Patent No. 1,890,231,granted December 6, 1932, on the application of Joseph C. Patrick andNathan M. Mnookin; such another article is disclosed in an applicationfor Letters Patent, filed March 22, 1933, by Werner W. Duecker, one ofthe present applicants, Serial No. 662,113. It is known that plastics ofthis class may be converted into elastic, flexible, rubber-like bodiesby vulcanization in the presence of an accelerator, together with zincoxide, and, ordinarily, other compounds commonly used in thevulcanization of rubber. The plastics, however, so responsive tovulcanization are narrowly limited to a small content of elementalsulphur.

We have discovered that, by employing certain compounds of otherparticular electro-positive elements, and, specifically a halide ofmercury, copper, silver, or lead, plastic bodies of the class definedmay by vulcanization be converted into rubber-like bodies; that thepresence of neither an accelerator nor other associated or assistingmaterial is required; that the product is of su perior quality; that itscontent of elemental sulphur may be high; and that if the material beprepared, applied to, and vulcanized upon, the surface of an article ofmetal, a union of intimate and durable character will be effected, themetal successfully coated with the elastic and inert product.

Masses containing, by weight, 25 parts of olefine sulphide and '7 5parts of sulphur, for example, may be converted into rubber-like bodiesby treating them at vulcanizing temperature 210 C.) with 2.5 parts of acompound of the class defined above,a halide of mercury, copper, silver,or lead.

This material may be simultaneously vulcanized and bonded directly tometal,-to steel, for example. This is an accomplishment not heretoforepossible with the olefine sulphides.

The material is prepared, advantageously, in a rubber mill, and toobtain a consistency such as to render rubber-mill operation easy, wehave found it desirable to include in the composition, not our metalcompound only, but an accelerator also, and associated with it a certainamount of zinc oxide. Such an addition of an accelerator in associationwith zinc oxide is a known expedient for rendering an olefine sulphideless viscous. This old expedient of reducing the viscosity of an olefinesulphide, as heretofore practiced, does not admit of association withthe sulphide of any substantial content of elemental sulphur; in ourpreparation however, a large elemental sulphur content is contemplatedand is advantageously provided.

In a companion application, filed Sept. 4, 1934, Serial No. 742,642, wedescribe and claim the composition with a mutual solution of sulphur andolefine sulphide of a halogen, or a halide, oxide, or sulphide of anelectro-negative elementarsenic, for example, or phosphorus, withconsequence and efiect that the viscosity of the mass is reduced. And itis possible, in the practice of this present invention, and in order torender the material responsive to rubber-mill operation to employ as anagent for reducing viscosity, not a rubber accelerator in associationwith zinc oxide, but a halogen or a halide, and oxide, or a sulphideofan electro-negative element-arsenic sulphide, for example. The ratio ofsuch addition will be carefully controlled, and only enough added toeffect the desired reduction in viscosity. An excess quantity has atendency to impair the desired rubber-like quality of the product inview.

The following mixture may be directly prepared and applied to andvulcanized upon steel. The result being a sheet of metal covered with aflexible, rubber-like film.

Sulphur 50 parts by weight Olefine sulphide 50 parts by weight Mercuricchloride 5 parts by weight Zinc oxide 5 parts by weight Diphenylguanidine 0.1? parts by weight Carbon black 33 parts The carbon blackcontent is of no intrinsic value in the process under consideration. Itsvalue is that it gives to the product a certain desired physicalcharacteristic.

The elastic flexible rubber-like masses, because they contain a largeproportion of sulphur, are

10 sion-resistant coating.

We claim as our invention:

A rubber-like body consisting of a mutual solution of sulphur andolefine sulphide in substantially the ratio of 75 parts of sulphur to 25parts of sulphide, vulcanized in the presence of substantially 2.5 partsof chloride of mercury.

WERNER W. DUECKER CLARON R. PAYNE.

